This invention relates in general to material moving tools and more particularly to material moving tools designed to decrease the sticking of material to the tool.
It is well recognized in the field of material moving tools, that tools such as shovels, post hole diggers, hoes, garden trowels, and front end loader and backhoe buckets, are used to move various materials such as soil. When the soil is wet, it becomes sticky and adheres to the material moving tool, such as a shovel.
This problem is particularly apparent, for example, when manually shovelling wet sticky soil out of and from around footings of foundations, sewer systems and lines, water lines, and buried cables. The fact that this is hard work is not as much of a detriment as the fact that the mud frequently sticks to the shovel and makes it virtually impossible to work efficiently. The worker cannot remove the mud from the shovel without some degree of difficulty.
When for example excavating a hole, the shovel is driven into the wet soil (material receiving position), and the worker lifts the shovel and consequently the soil and moves it to another location (material release position). At this location (material releasing position), the soil must be removed from the shovel blade. If the soil sticks to the shovel, extra effort must be made to remove it from the surface of the shovel blade so that the worker can continue digging the hole. In the past, workers have had to scrape the mud off of each shovel or beat the shovel on a rock or a board to get most of the wet soil off of the shovel. This involves substantial additional work. The worker may then continue to dig the hole. This process decreases the worker's efficiency by as much as 50% or more.
The same situation is also true, for example, when digging a hole with a post hole digger, moving wet snow with a snow shovel, or moving wet earth with hoes or garden trowels. This same situation also exists when front end loader or backhoe buckets are used to move wet earth.
It also well recognized that the weight of the material moving tool is an important factor in the efficiency of the worker. When a lighter tool is used, the worker can move more material with the same efficiency as moving less material with a heavier tool, since the weight of the tool and material is the same. When wet soil sticks to and is not removed from the tool, added weight is moved back and forth decreasing the amount of material moved and consequently the efficiency of the worker. The importance of this factor is readily recognized when considering the numerous times this repetitive action must be taken.
The weight of the material moving tool is also an important factor when a machine is used to manipulate the material moving tool such as a front end loader or backhoe bucket. When the tool is lighter, less effort is required of the machine, decreasing the wear and tear on the parts of the machine and the energy required to move the bucket from the material receiving position to the material releasing position.
It is also desirable to strengthen and reinforce the material moving tool to resist deformation when in use. When the worker inserts the tool, such as a shovel, into the wet soil and hits resistance, such as a rock, occasionally he will exert additional pressure tending to deform the shovel at its tip. This situation will be herein referred to as "tipping" where the tip of the shovel is deformed.
Accordingly, it is desirable to provide a material moving tool that minimizes the sticking of wet soil to the tool and accordingly increase the efficiency of the worker.
It is also desirable to provide a material moving tool that is light in weight and that allows the worker to easily move the tool between a material receiving position and a material releasing position.
It is desirable to provide a material moving tool with reinforcing means to resist deformation of the tool when forces are exerted on the tool.
Anderson, U.S. Pat. No. 1,146,609, discloses a shovel having a relatively few large elongated openings. These elongated openings are elongated in a longitudinal direction along the shovel blade in the direction of movement of the shovel into and out of the ground. A number of such openings are located about the blade including the central portion of the shovel. The elongated openings located in the central portion of the shovel taught by Anderson weaken the shovel blade in exactly the location and direction in which strength is required. Such elongated openings do not allow for maximizing the area of the openings in the shovel blade, while optimizing the strength of the shovel when such material is removed.
Other tools are disclosed in Palagonia, U.S. Pat. No. 3,638,986, Ball et al., U.S. Pat. No. 3,851,763 and Grint, U.S. Pat. No. 4,247,141.
A need has long been recognized for a material moving tool which minimizes the sticking of the material to the tool and a tool that is light in weight while having enhanced strength.